• Journal of Ginseng Research
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• v.23 no.2 s.54
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• pp.74-80
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• 1999

Excised cotyledon segments of ginseng zygotic embryos cultured on MS basal medium without growth regulators produced somatic embryos near the basal excised portion at a high frequency. The frequency of somatic embryo formation on the segments declined along with advancing zygotic embryo maturity. In immature cotyledons, all the cells of the epidermis and subepidermis were smaller and more densely cytoplasmic than those in mature cotyledons, and from which multiple cells participated in embryogenic division to form somatic embryos with multiple cotyledons and fasciated radicles (poly-embryos). But in germinating cotyledons, only the epidermal cells were densely cytoplasmic and singularly competent to develop into somatic embryos resulting in single-embryos with closed radicles. This result means that the origin and development of somatic embryos is determined according to whether the cells participating in embryonic division are in a single state or a massive state relative to cotyledon maturity.

• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.73-81
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• 2007

An efficient regeneration system was developed using leaf, petiole, and internode explants. Highly embryogenic callus was obtained following cultivation on MS basal nutrient supplemented with 2 $mg/{\ell}$ 2,4-D. Globular, heart, torpedo and cotyledon shaped somatic embryo were produced from the surface of embryogenic callus. Direct shoot regeneration without intermediate callus formation has been achieved on MS medium supplemented NAA and BAP. The percentage of response varies with different concentration of auxin and cytokinin treated individually or in combination. The best shoot regeneration response (54.28%) and number of shoot per explant (12.67) were achieved on the medium supplemented with 0.1 $mg/{\ell}$ NAA and 1 $mg/{\ell}$ BAP. The regenerated shoot transformed into young plant when cultured into elongation and root induction medium. More than 90% of in vitro propagated plants could survive when transferred to the greenhouse for acclimation. This optimized regeneration system can be used for rapid shoot proliferation and genetic transformation.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.317-332
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• 2004

Osteoblasts from alveolar bone may have an important role in the bone regeneration for periodontium, but their culture and characterization are not determined yet. The purpose of this study was to investigate the biological characteristics of primary explant cultured osteoblasts(PECO) from alveolar bone. Osteoblasts were isolated and cultured from alveolar socket of extracted tooth in children. To compare the characteristics, osteoblasts and gingival fibroblasts were cultured with DMEM at $37^{\circ}C$, 5% $CO_2$, l00% humidity incubator, and human fetal osteoblasts cell line(hFOB1) were cultured with DMEM at $34^{\circ}C$, 5%, $CO_2$ 100% humidity incubator. To characterize the isolated bone cells, morphologic change, cell proliferation and differentiation were measured. Morphology of PECO was small round body or cuboidal shape on inverted microscope and was similar with hFOB1. PECO became polygonal shape with stellate and had an amorphous shape at 9th passage in culture. PECO had significantly higher activity than that of gingival fibroblasts and hFOB1 in alkaline phosphatase activity. The expression of osteocalcin and bone sialoprotein in PECO was notably increased when compared with hFOB1 and gingival fibroblasts. These result indicated that PECO from alveolar bone in children has an obvious characteristics of osteoblast, maybe applied for the regeneration of bone.

• The Journal of Korean Medicine
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• v.27 no.1 s.65
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• pp.229-239
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• 2006

Objectives : Articular cartilage is a potential target for drugs designed to inhibit the activity of matrix metalloproteinases (MMPs) to stop or slow the destruction of the proteoglycan and collagen in the cartilage extracelluar matrix. The purpose of this study was to investigate the effects of KHBJs for cartilage-protective effect in human and rabbit articular cartilage explants. Methods : The cartilage-protective effects of KHBJ were evaluated by using glycosaminoglycan degradation assay, collagen degradation assay, colorimetric analysis of MMPs activity, and histological analysis in rabbit and human cartilage explants culture. Results : KHBJs significantly inhibited GAG and collagen release of rabbit and human cartilage explant in a concentration-dependent manner. Also, KHBJs inhibited MMP-3 and MMP-13 activities from IL-$1{\alpha}$-treated cartilage explants cultures. Histological analysis indicated that KHBJ004 reduced the degradation of the cartilage matrix compared with that of IL-$1{\alpha}$-treated cartilage explants. KHBJ004 had no harmful effect on chondrocytes viability or cartilage morphology in cartilage explants. Conclusions : These results indicate that KHBJs inhibits the degradation of proteoglycan and collagen through the downregulation of MMP-3 and MMP-13 activities without affecting the viability or morphology of IL-$1{\alpha}$-stimulated rabbit and human articular cartilage explants.

• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.57-65
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• 2005

The $F_1$ hybrid Red Coat is one of the most highly sought after cultivars of tomato in Australia and yields up to 7.5 $\cal{kg/plant}$. An experiment was conducted to de-termine the optimal strength and type of growth medium and sucrose concentration for shoot organogenesis of the Red Coat cultivar using cotyledonary explants. Two basal growth media, viz. MS and Gamborg' s $B_5$ at 0, 1/4, 1/2, full or double strength along with sucrose concentrations of 0, 0.5, 1.5, 3 or $5\%$, were evaluated using 25 replications. The main effects of treatment and their mutual interactions were evaluated for the proportion of explants that produced callus and/or shoots, number of shoots produced per explant, callus diameter and shoot height. The explants failed to produce shoots in the absence of mineral nutrient. Only a small proportion of the explants ($6\%$ with $B_5\;and\;3\%$ with MS) regenerated shoots in the absence of sucrose. Lower sucrose concentrations ($0.5-1.5\%$) along with full strength media were optimal for most of the traits studied. The $B_5$ medium outperformed MS medium for shoot organogenesis. For all the traits examined, significant differences in main effects (P < 0.05) and two-way interactions were detected, but no three-way interactions (medium type $\times$ medium concentration $\times$ sucrose concentration) were observed. Sucrose was found essential for the development of chlorophyll. Chlorophyll content increased with an increase in sucrose concentration up to $3\%$ and decreased at $5\%$ sucrose.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.21-24
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• 2001

Peucedanum japonicum $T_{HUNB}$ used as a edible and medicinal plants was investigated for in uitro regeneration. Callus formation occurred on leaf and stem explant cultures and showed spontaneous embryogenic and organogenic capability on MS basal medium supplemented with 0.1~5 mg/L NAA and 0~10 mg/L BA in dark. The regeneration was highest on the condition supplemented with 2.5 mg/L NAA and 10 mg/L BA. Development of the somatic embryo progressed through the globular, heart-shaped, torpedo-shaped and cotyledonary stage, typical of zygotic embryos. When the first somatic embryos was cultured on the medium supplemented with 0.2 mg/L NAA, secondary somatic embryo were induced with higher frequency on the hypocotyl then on the cotyledon and root.t.

• Journal of Plant Biotechnology
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• v.5 no.4
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• pp.221-224
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• 2003

Leaf explants of Ixeris sonchifolia produced adventitious shoots at a frequency of 100% when cultured on MS medium supplemented with combinations of various concentrations of 6-benzyladenine (BA) (0.44, 4.44, or 8.87 ${\mu}M$) and 0.54 ${\mu}M$ NAA, or MS medium supplemented with 22.19 ${\mu}M$ BA and 2.69 ${\mu}M\;\alpha$-naphthaleneacetic acid (NAA) after four weeks of culture. Each explants (approximately $3{\times}6mm$) produced greater than 70 shoots at a combination of 0.44 ${\mu}M$ BA and 0.54 ${\mu}M$ NAA. Leaf explants produced shoots at a frequency of greater than 80% even at as low as 0.13 ${\mu}M$ BA as the sole growth regulator. Upon transfer to one-third strength MS with 0.54 ${\mu}M$ NAA, excised adventitious shoots were rooted at a frequency of 100%. Regenerated plantlets were transplanted to potting soil and grown to maturity in a greenhouse. The competence of I. sonchifolia for plant regeneration via organogenesis appears to be greater than the competence of tobacco, currently the best model plant for organogenesis.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.193-196
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• 2009

Pinellia koreana K-H Tae & J-H Kim is a recently discovered Korea endemic medicinal plant species whose natural habitat is rapidly destroyed by industrial development. Described in this paper are culture conditions for high frequency plant regeneration via bulblet formation from leaf explant cultures of P. koreana. Leaf explants formed white nodular structures and off-white calluses at a frequency of 91.2% when cultured on MS medium supplemented with 2 mg/L BA and 0.5 mg/L NAA. However, the frequency of white nodular structures and off-white calluses formation was slightly decreased with an increasing concentration of NAA up to 4 mg/L, where the frequency reached 31.7%. Most petiole explants did not form white nodular structures and off-white calluses except the combination treatment of 2 mg/L BA and 2 mg/L NAA. Upon transfer onto MS basal medium, over 90% of nodular structures gave rise to numerous bulblets and developed into plantlets. Plantlets regenerated from bulblets were transplanted to potting soil and grown to maturity at a survival rate of over 95% in a growth chamber. Therefore, the in vitro plant regeneration system of P. koreana obtained in this study will be useful for mass propagation and long-term preservation of genetic resources of P. koreana.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.176-176
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• 2017

Hydropriming had positive effects on the time for germination to reach 50%, the germination index, the time to final germination percentage, and the number of uniform seedlings with enlarged cotyledons in in vitro germination of small watermelon. In addition, the highest shoot initiation was obtained from hydroprimed cotyledonary nodes ($95{\pm}6%$), followed by non-primed cotyledonary nodes ($78{\pm}6%$), hydroprimed cotyledons ($72{\pm}4%$), and non-primed cotyledons ($48{\pm}4%$). Meanwhile, no shoots were initiated from hypocotyls. The total number of shoots that initiated from cotyledonary nodes and cotyledon explants was insignificant, indicating that both cotyledons and cotyledonary node were good sources for the in vitro culture. Choosing explant sources that favor tetraploidy should be the key for producing higher polyploidy plants; a total of 10.5% of tetraploid regenerants were entirely identified from cotyledon explants. Cotyledons with highly differentiated cells might show higher variations than cotyledonary nodes with more preexisting meristematic cells. Cells of cotyledon tissue might undergo changes in ploidy level during differentiation of the culture, or it might be that some of the variations were already present in the tissues of the donor plant. Morphological changes in fruit length of tetraploid regenerants are genotype-dependent.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.201-207
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• 2012

This study was conducted to investigate the effect of supporting material and ionic strength of the MS medium on growth of strawberry plantlets cultured in vitro for the rapid mass production. Explants of $Fragaria$ $ananassa$ 'Houkouwase' in vitro were planted in the agar or Tosilee (commercial plug medium) medium as the supporting material and supplied with 1/4 MS, 1/2 MS or basal (as the control) MS medium in an autotrophic micropropagation. Plant height and root length were significantly greater when they were cultured in 1/2 MS medium as compared to those grown in the agar medium. Also, shoot fresh and dry weights, and leaf area in the 1/2 MS medium were greater than in 1/4 MS or basal MS medium. When plantlets were cultured in Tosilee medium and fed with the basal MS medium, plant height, root length, shoot fresh and dry weights, root fresh and dry weights, and leaf area were promoted and greater than those in plantlets cultured in the agar medium.